P3D Re: Re P3D Math-LESS solution for Realist close-ups

[Tom Deering <tmd@xxxxxxxxxxx>]

>>It solves something that always confused me. The 1/30 rule says my Realist
>>can't shoot anything closer than 7 feet, but the camera can be focused
>>down to 2.5 feet. Photos I've taken with close objects were sometimes
>>viewable, and sometimes not, for a reason I couldn't explain. <
>
>Not exactly.  The near limit for the Realist is 7 feet if your background
>reaches to infinity (or thereabouts).  Except, of course, for objects that
>properly come thru the window, to a moderate distance.  If you shoot closer
>than 7 feet, you need to restrict your background.

Thanks, Tony, for proving my point for me.  You _can_ shoot closer than 7
feet with a Realist, you just have to limit the depth in the shot.

So, as Tony points out, you can get closer if you limit the amount of depth
in your shot, by restricting what's in the background.  The whole point is,
how much?

The 1/30 rule doesn't do it.  The math is simple enough.  2.75 inches
between the lenses, times 30, equals six feet eleven inches.  So according
to the 1/30 rule, you can't get any closer than seven feet with your
camera.  Clearly wrong.

How much do you have to limit the background?  That's one of the things
these easy to read tables show.  How much to restrict the background so
that there is not too much depth in your shots.

Another good reason to try http://www.deering.org/curves.html

Cheers,

Tom



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